The short- and long-term effects of gene therapy using AAV-mediated RPE65 transfer to canine retinal pigment epithelium were investigated in dogs affected with disease caused by RPE65 deficiency. Results with AAV 2/2, 2/1, and 2/5 vector pseudotypes, human or canine RPE65 cDNA, and constitutive or tissue-specific promoters were similar. Subretinally administered vectors restored retinal function in 23 of 26 eyes, but intravitreal injections consistently did not. Photoreceptoral and postreceptoral function in both rod and cone systems improved with therapy. In dogs followed electroretinographically for 3 years, responses remained stable. Biochemical analysis of retinal retinoids indicates that mutant dogs have no detectable 11-cis-retinal, but markedly elevated retinyl esters. Subretinal AAV-RPE65 treatment resulted in detectable 11-cis-retinal expression, limited to treated areas. RPE65 protein expression was limited to retinal pigment epithelium of treated areas. Subretinal AAV-RPE65 vector is well tolerated and does not elicit high antibody levels to the vector or the protein in ocular fluids or serum. In long-term studies, wild-type cDNA is expressed only in target cells. Successful, stable restoration of rod and cone photoreceptor function in these dogs has important implications for treatment of human patients affected with Leber congenital amaurosis caused by RPE65 mutations.
Pubmed ID: 16226919 RIS Download
Mesh terms: Animals | Animals, Genetically Modified | Blindness | Blotting, Western | Carrier Proteins | Chromatography | DNA, Complementary | Dependovirus | Disease Models, Animal | Dogs | Electroretinography | Enzyme-Linked Immunosorbent Assay | Eye Proteins | Gene Deletion | Gene Transfer Techniques | Genetic Therapy | Genetic Vectors | Homozygote | Humans | Immunohistochemistry | Mutation | Promoter Regions, Genetic | Retinal Cone Photoreceptor Cells | Retinal Degeneration | Retinal Rod Photoreceptor Cells | Reverse Transcriptase Polymerase Chain Reaction | Time Factors | Transgenes | cis-trans-Isomerases
Publication data is provided by the National Library of Medicine ® and PubMed ®. Data is retrieved from PubMed ® on a weekly schedule. For terms and conditions see the National Library of Medicine Terms and Conditions.